(http://www.dpd.cdc.gov/dpdx/HTML/Aboutdpdx.htm: Most of the material is free of copyright and users are welcome to store and copy material in the public domain as they wish (please, kindly cite the source!). Copyrighted material includes: life cycle images of Blastocystis and Pneumocystis, and electron micrograph images of Gnathostoma; if users are interested in publishing these items, they must obtain permission from the original copyright holder.)